Description from Caro
and Sanchez (1971). Plants perennial, erect. Culms 55-90 cm tall, with
cleistogenes in the axils of the basal intravaginal innovation leaves. Leaf
sheaths open to the base, pubescent on the margins towards the apex;
ligules about 0.3 mm long, papery but with hairs about 1-1.5 mm
long on the back; blades to 30 cm long and 1-3 mm in width,
convolute-filiform or flat, stiff, more or less straight, pubescent on
the margins near the ligule, the lower surface smooth below, scabrlous
near the tip, the upper surface scabrous, somewhat sharp, the tip
somewhat sharp. Panicle 15-35 cm long, lax, with few to many
spikelets, sometimes partially included in the uppermost leaf
sheath. Glumes subequal, 7-11 mm long, lanceolate-acuminate,
3-veind, scabrous over the midvein and sometimes over the latera veins,
the midvein extending into an awnlike tip, the lateral veins much
shorter. Anthecium 5.5-6.5 mm long; callus 0.5-0.8 mm,
obconic, obtuse, with white straight hairs; lemma fusiform,
laterally compressed, 5-veined, pubescent over the midvein and between
the lateral veins near the margins, sometimes glabrous between the
midvein and the adjacent lateral veins, the lemma apex narrow and with a
ring of hairs about 1 mm long, without a crown; awn 1-2 cm long,
centric, capillary, persistent, twice geniculate, scabrous, the basal
segment 2-4 mm, the mid-segment 2-4 mm, and the bristle 6-12 mm; palea
much shorter than the lemm, coriaceous, 2-veined, the sides papery to
hyaline, pubescent over the veins and between and with short hairs at
the tip; lodicules 2-3, if 3, the third unequal in length, all
lodicules membranous, hyaline, glabrous, without veins; anthers 3,
about 3 mm long, ciliate at the tips. Caryopsis obovoid, about 3
mm long and 1.3 mm in diameter, with a persistent, excentric style base;
hilum linear, a little shorter than the caryopsis.